PROJECT SUMMARY Sub-Saharan Africa (sSA) is home to the fastest growing and youngest population in the world and includes countries with the highest HIV prevalence globally. More than half of sSA's population is under 25 years of age. Men and women aged 10 to 24, defined as `young people' by the United Nations Population Fund (UNFPA), represent one third of the sSA population. Young women in sSA who are economically and educationally disadvantaged are vulnerable to engaging in transactional sex. Sex workers under 16 and especially those new to sex work are much more susceptible than their older colleagues to violence, STIs and HIV. As sex work is illegal in Uganda, this increases the risk these young women face. Effective STI and HIV prevention, care, support, and reproductive health services are critical. Evidence on interventions that address uptake and adherence to HIV prevention services for high-risk populations is limited, but interventions that address young sex workers (YSW) are almost non-existent. As an administrative supplement to our R01 (NIMH R01MH109337, PI King), we are proposing to develop an enhanced retention strategy for HIV-negative women 15- to 24-years old who engage in high-risk sexual activity in Kampala, Uganda. We will embed this strategy within our existing cohort study) that has revealed the need for greater attention to the retention of this highly mobile and vulnerable group. The retention package will aim to include linked components that address both individual and structural factors affecting retention which then cascades into attention to sexual behavior and reproductive health decision making. The proposed additive components include: 1) opening a Saturday clinic; 2) adding text message reminders; 3) adding a hotline for questions or counselling; 4) involving queen mothers in health promotion and retention; 5) employing a mobile ACASI system, where some participants do their study visits in the field with help form study counsellors. The specific aims are (1) To conduct in-depth research to enhance our understanding of the dynamics of YWHR, agency, mobility and context of women (aged 15-24) engaged in high risk sexual behavior in Kampala, Uganda as well as barriers and opportunities to enhance retention in research and care; (2) To adapt clinic and research procedures for YWHR based on Aim 1 findings. We will follow our existing cohort of 450 HIV-negative women through 18 months post enrolment. The proposed strategy is responsive to several priority areas of the President's Emergency Plan for AIDS Relief and the World Health Organization regarding HIV prevention among young people. Our study represents one of the first studies to develop an integrated bio-behavioral-structural approach to HIV prevention among young women at high risk in resource-limited settings.